Java Activation Framework implementation from Apache Geronimo

Apache Geronimo is an open source application server developed by the Apache
Software Foundation and distributed under the Apache license. Geronimo is
currently compatible with the Java Enterprise Edition (Java EE) 5.0
specification.

The JavaBeans Activation Framework (JAF) extension to Java allows developers
to determine the type of an arbitrary piece of data, to encapsulate access to
it, to discover the operations available on it, and to instantiate the
appropriate bean to perform said operation(s). For example, if a browser
obtained a PNG image, JAF would help the browser to identify that stream of
data as a PNG image, and the browser can instantiate an object to display that
image.

Another DFSG free JAF implementation is available from the Glassfish project.